<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>5分钟掌握css样式</title>
  <link rel="stylesheet" href="style.css">
</head>
<body>
<div class="parent_container">
  <div class="child_container"></div>
  <div class="child_container_v2"></div>
  <div class="child_container_v3"></div>
</div>

<div class="parent_container_v2">
    我是传奇
</div>

<div class="parent_container_v3">
    <div class="pv3_s1">
    </div>
</div>

<div class="parent_container_v4">
    <div class="pv4_s1">
    </div>
</div>

<div class="parent_container_v5">
    <div class="pv5_s1">
    </div>
</div>

<div class="parent_container_v6">
    我是传奇
</div>

<div class="parent_container_v7">
    <div class="pv7_s1"></div>
</div>

</body>
</html>